Dementia Flashcards
Cortical dementia
Frontotemporal lobar degeneration is the third most common type of cortical dementia after Alzheimer’s and Lewy body dementia.
CJD
Frontotemporal lobar degeneration
There are three recognised types of FTLD
Frontotemporal dementia (Pick’s)
Progressive non fluent aphasia (chronic progressive aphasia, CPA)
Semantic dementia
Common features of frontotemporal lobar dementias
Onset before 65. Insidious onset. Relatively preserved memory and visuospatial skills. Personality change and social conduct problems
Picks
This is the most common type and is characterised by personality change and impaired social conduct. Other common features include hyperorality, disinhibition, increased appetite, and perseveration behaviours.
Focal gyral atrophy with a knife-blade appearance is characteristic of Pick’s disease. The term kinfe-blade is used to describe the gyri that are thin and narrow and resemble knives.
chronic progressive aphasia
Here the chief factor is non fluent speech. They make short utterances that are agrammatic. Comprehension is relatively preserved
Semantic dementia
Here the patient has a fluent progressive aphasia. The speech is fluent but empty and conveys little meaning. Unlike in Alzheimer’s memory is better for recent rather than remote events.
Pathological changes seen in FTLD
Macroscopic changes seen in Frontotemporal lobar degeneration include:-
Atrophy of the frontal and temporal lobes
Microscopic changes include:-
Pick bodies - spherical aggregations of tau protein
Gliosis
Neurofibrillary tangles
Senile plaques
Subcortical dementia
Binswanger’s disease
Dementia associated Huntington’s disease
Dementia associated AIDS
Dementia associated with Parkinson’s disease
Dementia associated with Wilson’s disease
Dementia associated with progressive supranuclear palsy
Characteristics of cortical dementia
Impaired memory
Impaired visuospatial ability
Impaired executive function
Impaired language
Characteristics of subcortical dementia
Generalised slowing of mental processes
Personality change
Mood disorders
Presence of abnormal movements
earliest neuropathological changes in Alzheimer’s
occur in the medial temporal lobe, which includes the hippocampus and parahippocampal gyrus.
Macroscopic changes seen in Alzheimer’s include:-
Hippocampal atrophy
Cerebral atrophy
Low brain weight
Enlargement of the inferior horn of the lateral ventricle
Microscopic changes seen in Alzheimer’s include:-
Senile plaques (extracellular deposits of beta amyloid in the gray matter of the brain)
Neurofibrillary tangles (intracellular composition of tau protein)
Gliosis
Degeneration of the nucleus of Meynert
Hirano bodies
Dementia Investigation (NICE)
NICE guidelines suggest the following investigations in people with dementia:-
routine haematology
biochemistry tests (including electrolytes, calcium, glucose, and renal and liver function)
thyroid function tests
serum vitamin B 12 and folate levels
Structural imaging should be used in the assessment of people with suspected dementia to exclude other cerebral pathologies and to help establish the subtype diagnosis. Magnetic resonance imaging (MRI) is the preferred modality to assist with early diagnosis and detect subcortical vascular changes, although computed tomography (CT) scanning could be used. Imaging may not always be needed in those presenting with moderate to severe dementia, if the diagnosis is already clear.
Perfusion hexamethylpropyleneamine oxime (HMPAO) single-photon emission computed tomography (SPECT) should be used to help differentiate Alzheimer’s disease, vascular dementia and frontotemporal dementia if the diagnosis is in doubt. People with Down’s syndrome may show SPECT abnormalities throughout life that resemble those in Alzheimer’s disease, so this test is not helpful in this group.
If HMPAO SPECT is unavailable, 2-[18F]fluoro-2-deoxy-d-glucose positron emission tomography (FDGPET) should be considered to help differentiate between Alzheimer’s disease, vascular dementia and frontotemporal dementia if the diagnosis is in doubt.
Dopaminergic iodine-123-radiolabelled 2-carbomethoxy-3-(4-iodophenyl)-N-(3-fluoropropyl) nortropane (FP-CIT) SPECT should be used to help establish the diagnosis in those with suspected dementia with Lewy bodies (DLB) if the diagnosis is in doubt.
Testing for syphilis serology or HIV should not be routinely undertaken in the investigation of people with suspected dementia. These tests should be considered only in those with histories suggesting they are at risk or if the clinical picture dictates.
A midstream urine test should always be carried out if delirium is a possibility
Clinical presentation should determine whether investigations such as chest X-ray or electrocardiogram are needed.
Cerebrospinal fluid examination should not be performed as a routine investigation for dementia. Cerebrospinal fluid examination should be used if CreutzfeldtJakob disease or other forms of rapidly progressive dementia are suspected.
Electroencephalography should not be used as a routine investigation in people with dementia. Electroencephalography should be considered if a diagnosis of delirium, frontotemporal dementia or CreutzfeldtJakob disease is suspected, or in the assessment of associated seizure disorder in those with dementia.
Brain biopsy for diagnostic purposes should be considered only in highly selected people whose dementia is thought to be due to a potentially reversible condition that cannot be diagnosed in any other way.
Treatment of Lewy body dementia
Evidence on the treatment of Lewy Body dementia is sparse. There is one RCT which showed some (all be it little) benefit from rivastigmine.